中国环境科学

作者：孙凤飞, 王秀, 毛雨梦, 刘珂, 刘娟

单位：1. 南京农业大学资源与环境科学学院, 土壤有机污染控制与修复研究所, 江苏 南京 210095;2. 南京市畜牧家禽科学研究所, 江苏 南京 210017

关键词：除草剂,可移动质粒RP4,抗生素抗性基因,水平迁移,二亲接合

基金：国家自然科学基金资助面上项目(42377018);江苏省自然科学基金资助面上项目(BK20221519)

The spread of antibiotic resistance genes (ARGs) in farmland ecosystem is directly related to human health, and has attracted much attention in recent years. Herbicides are common chemical reagents widely used in farmland ecosystem, and until now, little information has been known about its effects and mechanisms on horizontal gene transfer (HGT) of ARGs between bacteria. In this study, with Escherichia coli DH5α(carrying RP4 plasmid with TetR, AmpR, KanR) as the donor and E. coli HB101as the recipient, a series of diparental conjugation experiments were conducted to investigate the effects of butachlor, paracetamol and glufosinate on HGT of ARGs via plasmid-mediated conjugation. Furthermore, the mechanisms involved were also clarified from cell membrane permeability, intracellular ROS content, and the transcription levels of genes related to conjugation. The results showed that 100~800mg/L of butachlor and 40~160mg/L of paracetamol could promote the conjugation transfer of plasmid RP4. Under test concentrations, butachlor stimulated the intracellular production of ROS, while paraquat reduced the ROS level. Under the treatment of butachlor or paracetamol, the surface of the recipient bacterium appeared obvious shrinkage, and with the increase of concentration, the pore and even break appeared. Butachlor (400~800mg/L) and paraquat (40~80mg/L) could both increase cell membrane permeability, inhibit the korA transcription and promote the transcription of trbBp、trfAp and traA, thus promoting the conjugation transfer of RP4. Under test concentrations, there was only a little effect of glufosinate on RP4 conjugation, as well as cell membrane permeability, intracellular ROS content and transcription of conjugation-related regulatory genes. This study indicated that widespread use of herbicides in agricultural production could affect the HGT of ARGs via plasmid-mediated conjugation, and the application of reasonable types and concentrations of herbicides could reduce the ARG transmission in both soil environments and plants.

来源：2024年第11期

《中国环境科学》期刊编辑部

查看中国环境科学杂志2024年第11期